BIOL G220: Ch. 19 Flashcards
Terms and concepts from Ch. 19: Senses
stimuli
sensory information our bodies are constantly exposed to
sensation
our conscious awareness to stimuli
receptors
detect stimuli in our body
general senses (5)
temperature, pain, touch, stretch, pressure
special senses (5)
gustation, olfaction, vision, equilibrium, audition
sensory receptors can be structurally _____ (the eye) or very simple (dendritic endings in the nose)
complex
receptors act as ___, where they can change on form of energy into another
transducers
transducers
change one form of energy into another
receptive fields
area through which the sensitive ends of a receptor cell are distributed
general sense receptors are distributed throughout the..
skin and organs
special sense receptors are housed in..
complex organs in the head
criteria used to describe receptors (3)
- receptor distribution
- stimulus origin
- modality of stimulus
receptor distribution (3)
somatic receptor
visceral receptor
special senses
somatic receptor
found within the body wall and structurally simple; receptors for chemicals, temperature, pain, touch, proprioception, and pressure
visceral receptors
found within the walls of the viscera; they respond to chemicals, temperature, and pressure
special senses
located only in the head, structurally complex; gustation, olfaction, vision, equilibrium, and hearing
stimulus origin (3)
exteroreceptors
interoreceptors
proprioceptors
exteroreceptors
found in skin or mucous membranes such as nasal and oral cavities and vagina; detect stimuli in external environment
interoceptors
found in the walls of viscera; detect stimuli within the body i.e. stretching, oxygen, temperature, and pressure
proprioceptors
found in muscles, tendons and joints; detect body and limb movement (sense of position of state of contraction)
modality of stimulus (6)
chemoreceptors thermoreceptors photoreceptors mechanoreceptors baroreceptors nociceptors
chemoreceptors
detect specific molecules dissolved in fluid
thermoreceptors
detect changes in temperature
photoreceptors
detect changes in light intensity, color, and movement of light
mechanoreceptors
detect physical deformation due to touch, pressure, vibration, and stretch
baroreceptors
detect pressure changes within body structures
nociceptors
detect tissue damage and pain
phantom pain
sensation associated with a part of the body that has been removed
How is phantom pain likely?
sensory cell bodies from limb remain alive as part of the dorsal spinal root; this provides sensation to the CNS despite the removal of the limb
phantom pain aka
phantom limb syndrome
referred pain
when impulses from certain viscera are perceived as originating not from the organ but in a dermatome of the skin
tactile receptors aka
touch receptors
tactile receptors are the most ___ type of receptor
numerous
tactile receptors
mechanoreceptors that react to touch, pressure, and vibration stimuli
tactile receptors located in.
dermis and subcutaneous layers of skin
type of tactile receptors (2)
unencapsulated
encapsulated
unencapsulated tactile receptors
endings not wrapped in connective tissue or glial cells
encapsulated
endings wrapped in connective tissue or glial cells
unencapsulated tactile receptor types (3)
free nerve endings
root hair plexuses
tactile discs
free nerve endings
found in papillary of dermis and deep epidermis; temperature and pain
root hair plexuses
surround hair follicles in dermis; hair movement
tactiles discs
associated with tactile cells in stratum basale of epidermis; light touch
encapsulated tactile receptor types (4)
end bulbs
lamellated corpuscles
bulbous curpuscles
tactile corpuscles
end bulbs
in skin and mucous membranes of oral and nasal cavities, vagina, and anal canal; light pressure and vibration
lamellated corpuscles
in dermis, subcutaneous tissue, synovial membranes, and some viscera; deep pressure
bulbous corpuscles
in dermis and subcutaneous layer; deep pressure and distortion
tactile corpuscles
in dermal papillae, especially lips, palms, eyelids, nipples, and genitals (touch)
gustation
sense of taste
gustatory cells
taste receptors housed in specialized organs termed taste buds
taste buds are located..
on the dorsal surface of the tongue in epithelial and connective tissues elevations called papillae
type of papillae
filiform papillae
fungiform papillae
vallate papillae
foliate papillae
mass majority of taste buds are..
vallate papillae
each taste bud is composed of numerous cells called ___ ____, which are enclosed in ___ _____
gustatory cells; supporting cells
the taste hair extends through the __ ___
taste pore
taste molecules within the oral cavity activate the __ ___
taste hairs
difference between gustatory cell and supporting cell
sensory nerve to gustatory
taste sensations (5)
- sweet
- salt
- sour
- bitter
- umami
olfaction
sense of smell
olfaction detects..
odorants
olfactory epithelium consists of three distinct cell types:
- olfactory receptor cells
- supporting cells
- basal cells (allows regeneration)
Deep to the olfactory epithelium is the..
lamina propria
olfactory hairs
free nerve endings at the apical end of the olfactory receptor cells, project through the mucous covering the olfactory epithelium
olfactory hairs contain receptors for __ ____ (dissolved in mucus)
airborne molecules
receptors for vision reside in the..
eye
accessory strx of the eye prevent __ ___ from coming in contact with the eye and ensure the surface o the eye remains ___ and ____
foreign objects; clean; moist
external accessory structures of the eye include (4)
eyebrows
eyelashes
eyelids
tarsal glands
eyebrows
curved row of thick short hairs along the superior orbital ridge; prevent sweat from dripping into the eye
eyelashes
hairs on the margins of the eyelids that prevent large foreign objects from contacting the eyes
eyelids
movable anterior protective covering for the eye
tarsal glands
located within both eyelids; contain sebaceous galnds to prevent tear overflow and the eyelids from sticking together
conjunctiva
stratified squamous epithelium that lines the anterior surface of the eye (but not the cornea) and the inner surface of the eyelid
conjunctiva also contain __ ___ to lubricate and moisten the eye
goblet cells
palpebral
eyelid
commisure
coming together
fissure
hole
pupil
hole
sclera is covered by..
conjunctiva
iris
color of the eye
muscles of eye (6)
levator palpebrae superioris muscles superior rectus muscle inferior rectus muscle orbicularis oculi muscle inferior oblique muscle orbicularis oculi muscle
from the ocular conjunctiva to the palpebral conjunctiva, must go through the..
conjunctival fornix
lacrimal apparatus
produces, collects, and drains lacrimal fluid from the eyes
tears lubricate the..
anterior surface of the eye
tears help to prevent bacterial infections because they contain an antibiotic-like enzyme called
lysozyme
the eye is a spherical organ about ____ in diameter
2.5 cm
principal layers that form the wall of the eye
- fibrous tunic
- vascular tunic
- retina
fibrous tunic regions (2)
cornea
sclera
cornea
transparent, avascular layer that receives oxygen and nutrients from lacrimal fluid and aqueous humor
sclera
makes up the majority of the fibrous tunic considered the ‘white’ of the eye and allows for the attachment of the extrinsic eye muscles to the eye
vascular tunic regions (3) from posterior to anterior
- choroid
- ciliary body
- iris
choroid
contains a vast network of capillaries, which supply nutrients and oxygen to retina
ciliary body
composed of ciliary muscles and ciliary processes; changes lens shape
iris
pigmented part of the anterior eye; defines the pupil and controls amount of light entering the eye
anterior cavity is anterior from the
lens
anterior chamber of anterior cavity is the space between..
iris and cornea
posterior chamber of the posterior cavity is the space from..
lens to iris
hyaloid canal
left of what the central nerve/artery of retina used to penetrate in posterior cavity from before fetus approaches term
pupillary constriction is caused by..
sphincter pupillae contraction through parasympathetic innervation
pupillary dilation constriction is caused by
dilator pupillae contraction through sympathetic innervation
retina
internal layer of the eye wall
layers of retina (2)
pigmented layer
neural layer
pigmented layer of retina
attached to the choroid, absorbs light energy that passes through the retina and provides photoreceptors with vitamin A
neural layer
houses photoreceptors and other associated neurons
neural layer layers
- photoreceptor cells
- bipolar cells
- ganglion cells
photoreceptor cells
outermost layer composed of rods and cones
bipolar cells
synapse with photoreceptors and ganglion cells
ganglion cells
innermost layer of the retina; axons of these cells leave the retina and form the optic nerve (CN II)
Rods are much more ____ than cones; can sense 1 photon at a time to be activated
sensitive
optic disc (neural layer)
‘blind spot’ on the retina; lacks photoreceptors
optic disc location
where ganglion cell axons exit retina to form optic nerve (CN II) and retinal arteries and veins enter and exit retina
fovea centralis (neural layer)
area of retina that contains the highest proportion of cones and almost no rods
fovea centralis is the area of ____ vision
sharpest
lens
transparent, deformable structure suspended behind the pupil by suspensory ligaments
____ _____ are attached to outer capsule of the lens and when ligaments are either relaxed or tense, it causes a change in the shape of the lens
suspensory ligaments
ciliary muscles
of the ciliary body, it causes tension
cavities of the eye
internal space of the eye that is subdivided by the lends into two cavities
cavities of the eye (2)
anterior cavity
posterior cavity
anterior cavity of the eye
between the lens and the cornea; filled with aqueous humor
posterior cavity of the eye
between the lens and the retina; filled with vitreous humor
visual pathways
anatomica pathway between light input and the perception of vision
visual pathways steps (5)
- light is detected by photoreceptors
stimulus is passed to bipolar and ganglion cells - axons of the ganglion cells form the optic nerve which converge at the optic chiasm (some axons decussate)
- ganglion axons enter optic tract and project to either the superior colliculi or lateral geniculate nucleus of the thalamus
- from the thalamus, axons project to the primary visual cortex
the ear contains organs of ___ and ___ and supportive structures
equilibrium; hearing
anatomic regions of ear
- external ear
- middle ear
- inner ear
external ear parts (3-4)
auricle
external acoustic meatus
tympanic membrane
cerumen (glands produce)
auricle
skin covered, funnel-shaped, elastic cartilage-supported structure
external acoustic meatus
bony tube to which auricle leads to and which ends at the tympanic membrane
tympanic membrane
eardrum; external acoustic meatus ends here
cerumen
waxlike secretion glands deep within external auditory meatus create
middle ear parts (6)
tympanic cavity auditory tube auditory ossicles malleus incus stapes
tympanic cavity
filled with air and medial to tympanic membrane
auditory tube
contained in tympanic cavity; connects to the nasopharynx
auditory ossicles
contained in tympanic cavity; smallest bones of body - protected by stapedius and tensor tympani muscles (stabilized)
auditory ossicles (3)
malleus
incus
stapes
malleus (hammer)
attached to tympanic membrane and articulates with incus
incus (anvil)
middle of three bones; articulates with the stapes
stapes (stirrup)
fits into the oval window on lateral wall of inner ear
auditory ossicles function
attenuate sounds
stapedius is the __ muscle in the body
shortest
inner ear location
petrous portion of temporal bone
bony labyrinth
spaces in inner ear
membranous labyrinth
fluid-filled tubes and spaces within the bony labyrinth
receptors for ___ are housed within the sensory epithelium lining of the ___ ___
equilibrium; membranous labyrinth
perilymph
filling the space between the walls of the bony and membranous labyrinths
perilymph function
supports and protects the membranous labyrinth
endolymph
fluid contained in the membranous labyrinth
regions of bony labyrinth (3)
- vestibule
- semicircular canals
- cochlea
vestibular complex
area composed by vestibule and semicircular canals
vestibule parts (2)
- utricle
2. saccule
semicircular ducts
the membranous labyrinth within the semicircular canals
cochlear duct
membranous labyrinth housed by cochlea
maculae (of vestibule) location
along the internal walls of the utricle and saccule
sensory epithelium lining the two ____ contains hair cells and supporting cells
maculae
hair cells
sensory receptors for both equilibrium and hearing
on their apical surface, they contain more than 50 stiff microvilli called ___ and one long cilium called a ______
stereocilia; kinocilium
when the stereocilia and kinocilium are bent..
this translates electrical activity sent to the brain via the vestibular nerve
hair cells in the ___ and ____ detect position of the head
utricle; saccule
stereocilia and kinocilia projecting hair cells are embeded within a ___ ______ that covers the surface of the epithelium
gelatinous mass
otoliths
small calcium carbonate crystals covering gelatinous mass
otholithic membrane
otoliths + gelatin layer
When the head moves, the otoliths _____ on the underlying gelatin layer, the result of which is the bending of the ___ and ____ of the hair cells which then translates into ____ and _____ ____ of the head
push; stereocilia; kinocilium; orientation; linear acceleration
semicircular canals are ____ with the utricle
continuous
types of semicircular canals (3)
anterior, posterior, lateral
receptors within the semicircular ducts detect ___ _____ of the head
rotational movement
ampulla
expanded region within each of the three semicircular canals
crista ampullaris
elevated region in ampulla that is covered by an epithelium of hair cells and supporting cells
cupula
gelatinous dome overlying the crista ampullaris and has stereocilia and kinocilia embed into it
when the head rotates, the endolymph moves and ____ against the cupula and bends the ______
pushes; stereocilia
hair cells within the ____ and the semicircular canals detect movement of endolymph
vestibule
vestibular nuclei
projected by vestibular axons located in the superior medulla oblongata
impulse travel destinations through vestibular sensation pathways (3-5)
impulses go to..
- spinal cord for muscle tone and balance
- brainstem for reflexive motor activities associated with eye movements and head and neck functions
- cerebellum, thalamus, and cerebral cortex
cochlea
organ for hearing
bony labyrinth surrounds the cochlear duct and is split into two chambers (2)
- scala vestibuli
2. scala tympani
spiral organ
located within the cochlear duct and detects movement of endolymph
spiral organ contains thick sensory epithelium including ___ ___ and __ ___
hair cells; supporting cells
tectorial membrane
overlying gelatinous mass of spiral organ of which stereocilia of the hair cells project into
soundwave pathway through the ear steps (5)
- sound waves enter ear and cause the tympanic membrane to vibrate
- tympanic membrane vibration moves auditory ossicles; sound waves are amplified
- stapes at the oval window generates pressure waves in the perilymph within the scala vestibuli
- pressure waves cause the vestibular membrane to move, resulting in pressure wave formation in the endolymph within the cochlear duct and displacement of a specific region of the basilar membrane. hair cells in the spiral organ are distorted, initiating a nerve signal in the cochlear branch of CN VIII.
- remaining pressure waves are transferred to the scala tympani and exit the inner ear via the round window.